My Dear Shotgun -
Since the demise of the Webleys, the Iver Johnston, and the H&R, modern-designed breaktops have had to
face the realities that :
1) the design is not as strong as a solid frame revolver.
and
B) The market seems well served by the S&W clones and old stock originals
I have found only Two
modern efforts, the MP412, and the Detonics.
I had thought that Mateba had once put out a breaktop, but apparently I have been deluded by watching too many Japanese Cartoons.
1) ~ 1990 Russian MP412 REX
http://en.wikipedia.org/wiki/MP412_REX late 1990s (prototypes only—never reached production stage)
I can;t find much more as I do not read Russki
2) 1982 the DETONICS folks filed a patent for a SS top break revolver
According to a flyer It was a 7-shot .44 Magnum. It never got past the drawing board.
US Patent #4,539,771 - Handgun of the revolver type.
http://www.google.com/patents/US4539771#v=onepage&q&f=falsehttp://pics.livejournal.com/casatic/pic/006xehbt/s640x480thus, we see that modern efforts, from reasonably well-funded (at the time ) extant corporations with actual factories
building actual products were full of fail.
yhs
prof marvel